Direct contact of high-k/Si gate stack for EOT below 0.7 nm using LaCe-silicate Layer with V fb controllability

A direct high-k/Si gate stack has been proposed for gate oxide scaling. With LaCe-silicate, an EOT of 0.64 nm with an average dielectric constant (k av ) of 17.4 has been obtained and an extremely low gate leakage current (J g ) of 0.65 A/cm 2 . The flatband voltage (V fb ) can be controlled by the compositional ratio of La in the LaCe-silicate layer. Furthermore, incorporation of Ge atom into the silicate layer can effectively shift the V fb to positive direction.